When you defecate in and around your lovers mouth and he/she/it performs a bloodcurling scream and exhales fecal matter. Much like a dragon, without the feces. Most commonly used in Lord of the Rings. Most notable occurence is when Gandalf performed this on Legolas during the Battle of Gondor.

Late one night after Alec got done supervising his church youth group, he came home to see his Homosexual lover Remi engaged in an affair with Eric. A couple days later, Alec told Remi to come into the room. When Remi came into the room, Alec suprised him by shitting all over his mouth and down his throat. Enraged by this, Remi let out a huge roar expelling poo from his mouth.

After witnessing this act of revenge, Lily Twodicks proclaimed "eeeeeewwwww why did you just give him a Middle Earth Mud Dragon?"